(a) Field of the Invention
The present invention relates to an objective lens system for an endoscope.
(b) Description of the Prior Art
A retrofocus type lens system is known as an objective lens system for an endoscope which is, for example, disclosed in Japanese Published Unexamined Patent Application No. 121547/74, and illustrated in FIG. 1. This objective lens system was convenient for a principal ray 2 to incident vertically on an image guide 1. But, the objective lens system of this type had defects such that distortion was large, the total length was long, and the outside diameter of the objective lens system was large compared with the image height.